Performance of Ductile Iron Pipe

Ductile iron pipe is a kind of cast iron, an alloy of iron, carbon, and silicon. Graphite in ductile cast iron is in the form of spheroids. Generally, the size of the graphite is 6-7. The quality requires that the spheroidization level of the cast pipe be controlled to be 1-3 (spheroidization rate ≥80%), so the material itself is mechanical The performance has been better improved, with the essence of iron, the performance of steel. The annealed ductile iron pipe has a metallographic structure of ferrite plus a small amount of pearlite, which has better mechanical properties. The ductile iron pipe is mainly called a centrifugal ductile iron pipe. It has the essence of iron, the properties of steel, excellent anti-corrosion performance, good ductility, good sealing effect, simple installation, mainly used in municipal, industrial and mining enterprises water supply, gas transmission, oil, and so on. It is the first choice for water supply pipes and has a high-cost performance. Compared with PE pipes, ductile ink pipes are easier and faster to install than PE pipes in terms of installation time, and have better internal and external pressure after installation; from the perspective of airtightness and corrosion resistance, ductile ink tubes have better airtightness after installation, and A variety of anti-corrosion methods can be used to improve the anti-corrosion performance; from the perspective of hydraulic performance, because the specifications of ductile pipes generally refer to the inner diameter, the specifications of PE pipes generally refer to the outer diameter, because under the same specifications, the ductile tube can achieve greater runoff; From the perspective of comprehensive installation and maintenance costs, the ductile tube has a more superior cost performance. The inner wall is sprayed with zinc, cement mortar, and anticorrosive materials.

Anti-corrosion treatment

1. Asphalt paint coating

The asphalt paint coating is used to transport gas pipelines. Preheating the pipe before painting can improve the adhesion of asphalt paint and accelerate drying.

2. Cement mortar lining + special coating

This kind of internal anti-corrosion measures is suitable for pipelines that transport sewage and can improve the corrosion resistance of the lining.

3. Epoxy coal pitch coating

The epoxy coal tar coating is suitable for both gas pipelines and sewage pipelines. It is a two-component coating with high adhesion and a very smooth surface.

4. Epoxy ceramic lining

The epoxy ceramic lining is suitable for sewage pipes and gas pipes, but due to the difficult manufacturing process and high cost, it has certain limitations in use. The epoxy ceramic lining has high adhesion and smoothness and is an excellent anti-corrosion coating.

5. Aluminate cement coating or sulfate cement coating

Both of these special cement coatings are suitable for the internal anti-corrosion of ductile iron pipes for sewage pipelines and improve the corrosion resistance of the acid and alkali components in the sewage.

6. Polyurethane coating

It is a new type of green special coating developed to meet the needs of environmental protection. It has good wear resistance and corrosion resistance.

The above information is provided by the DI pipe manufacturer.